2009 human H1N1 Flu
Penn Vet update on the human H1N1 influenza outbreak
May 4, 2009
Penn Vet faculty and research staff are involved in influenza research, participating with the National Institutes of Health MIDAS program. The serious 1983-1984 outbreak of highly pathogenic avian influenza (H5N2) in Pennsylvania poultry flocks was an important wake up call and a graphic demonstration of how damaging influenza can be to the economy of Pennsylvania even if it is restricted to animals (which that outbreak was).
Viruses underlying outbreaks of influenza in people unfortunately can originate from animals, either domestic or wild. While most flu viruses are specially adapted to infect a single animal species, some animals such as pigs also can be infected by flu viruses from birds and humans. Once inside a common cell, genes from these different flu viruses mix or reassort to make a new virus and start to replicate. The resulting virus might lose the ability to infect the pig, but develop a predilection for a new species, such as humans.
The virus causing the present outbreak of human disease was originally mislabeled as a "swine flu" because many of its genes are similar to other genes found in swine influenza viruses. Interestingly, the present H1N1 virus infecting people appears to have its genetic origins from pig, bird and human influenza viruses. Accordingly, the new virus has been officially given the name influenza A/ H1N1 virus.
As veterinary scientists, one of our jobs is to limit the opportunities for flu viruses to replicate and reassort. We do this by preventing or controlling influenza outbreaks in poultry and swine. This does two things: it reduces the economic impact of the infection in animals and it reduces the probability of a new virus emerging that could cause epidemics in people. However, influenza viruses infect a huge range of wild and domestic animals and it is to be expected that, every so often, a new human-adapted virus will emerge despite our best efforts.
The United Nation's Food and Agriculture and World Health Organization (FAO), along with the World Trade Organization (WTO) and the World Organization for Animal Health issued a joint statement saying there is no evidence that the virus is spread by food, and there is no risk of getting the infection from eating properly prepared pork.
Researchers in veterinary diagnostic labs across the U.S. have sequenced hundreds of viruses previously isolated from pigs and have not found this novel H1N1 virus that is causing the human disease. During a week of confusion about the pig’s role in this human disease, thousands of pigs were scheduled for euthanasia abroad and several countries banned the import of US pork products. The situation has become more complicated as a result of a herd in Canada being diagnosed with the new flu virus, apparently infected by a sick worker returning from Mexico. The prices farmers are receiving for their pigs dropped by as much as 10% across the country, and it is expected to take several weeks for these markets to recover. Penn Vet swine clinicians continue to work with swine farmers to help them through these difficult times.
What Penn is Doing About 2009 H1N1 Flu
Guidelines for Penn Vet faculty, staff and students at both campuses.
University of Pennsylvania answers questions about the H1N1 flu.
Influenza in Swine
Diagnostic Testing In Pennsylvania.
Contact a Swine Expert.
National Institutes of Health MIDAS Program.
Centers for Disease Control and Prevention.
Pennsylvania Dept of Health.
National Pork Producers Council.
American Association of Swine Veterinarians.
Name Change - Feds drop 'swine flu,' for 'H1N1 flu' (USA Today).
Pork is Safe (USA Today).
Can My Pet Get Swine Flu? (ASPCA).
Pennsylvania Veterinary Medical Association (PVMA).
Dr. Gary Smith and Dr. Sherrill Davison comment on the H1N1 flu.